Flammable base with fire-retardant protective coating



United States Patent Office 3,312,565 Patented Apr. 4, 1967 3,312,565 FLAMMABLE BASE WITH FIRE-RETARDANT PROTECTIVE COATING Eric T. Rayner, David A. Yeadon, Lucien L. Hopper, Jr., and Harold P. Dupuy, New Orleans, and Frank G. Dollear, Pearl River, La., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Original application Mar. 14, 1962, Ser. No. 179,818, now Patent No. 3,269,989, dated Aug. 30, 1966. Divided and this application Apr. 18, 1966, Ser. No. 543,045

3 Claims. (Cl. 11772) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This is a division of application Ser. No. 179,818, filed Mar. 14, 1962, now U.S. Patent 3,269,989.

This invention relates to intumescent, surface protective compositions and in particular to the methods and to the specific ingredients used for preparing these coating compositions.

It is an object of this invention to provide protective coating compositions that in addition to being fire retardant are capable of withstanding durably the exposure to the elements, that is requisite for the use of protective coatings as exterior paints.

The fire-retardant, surface coatings that are the ultimate products of this invention can be applied to surfaces that are inherently flammable such as paper, cardboard, wood, fibrous wall board and the like as well as to non-flammable surfaces such as metal, plasterboard, and the like.

It is another object of this invention to prepare certain new and unique chemical compounds, the polyesters of aliphatic diyne-diol compounds with dibasic acids all of which compounds exhibit highly eflicient intumescing properties under the influence of heat. Such materials are particularly valuable ingredients in fire-retardant protective coating compositions.

The problem of formulating fire-retardant, surface protective coatings is old and many solutions have been proposed and employed. One obvious method is to substitute non-flammable materials for the combustible ingredients in the surface coating composition and to obtain thereby some semblance of fire protection for the coated surface. This method has been widely practiced.

The use of certain groups of chemicals, such as the borates, the phosphates, and the silicates in solution to coat and thereby to protect wooden surfaces against fire is old. The efifects of such treatments are at best transient since they provide no physical barrier between the surface being protected and the flame.

Old also is the use of thick non-flammable coatings made from materials, such as clay and gypsum. -Th-ese materials although they afford a physical barrier and hence protect the surface somewhat better than the first mentioned surface treatments suffer the serious defect of being easily leached. Lack of water resistance precludes the use of these methods for providing protection on exterior surfaces.

The addition to the protective coating composition of certain materials that, when heated, will liberate copious quantities of non-combustible gases and thereby smother the flame and the addition of ingredients in a surface coating composition that will melt and form a glass-like non-flammable protective barrier under the influence of heat are still other approaches to the production of fireretardant, surface protective coatings.

The best current method for producing a fire-retardant,

surface protective coating is to incorporate within the coating composition a material or materials that, when heated, will liberate a considerable quantity of gas, which latter (gas) will cause the film 0f the coating composition to swell, forming a noncombustible, insulating barrier over the coated surface. This isolates the fire-vulnerable surface from flame by a fire-resisting, heat-insulating barrier. It is to this method of producing fire-retardant surface protective coatings that the instant invention is directed.

Numerous materials that intumesce under the influence of heat are well known to the art of formulating fireretardant coating compositions. Many are natural products such as isano oil, gum tragacanth, gum arabic, Irish moss, and starch. The gas-producing ability and hence the intumescing efiiciency of these known materials is quite indifferent when contrasted with that of the diynediol and butynediol polyesters, and the water-saturated, synthetic zeolites that are subjects of this invention. Moreover, whereas the known and heretofore employed intumescent materials are utilized as simple additives incorporated by mechanical mixing into the surface protective coating, the new polyester materials of this invention are, if desired, capable of being incorporated into the surface coating composition by chemical reactions.

As will be shown, the specific intumescent materials of this invention whether admixed or chemically bonded Within the coating composition are not only superior to conventional intumescing materials by a factor of several hundred percent, but of more importance, theypermit the preparation of protective coating compositions that can be pigmented and protective coating compositions that possess sufiicient inherent stability to Water, extremes of temperature, and exposure to sunlight so that the coatings may be employed as exterior paints. This latter feature makes the surface protective coatings prepared in accordance with this invention singular in the field of fireretardant coatings of the intumescent type.

We have discovered that compounds represented by the formulas which are conjugated diacetylene diols wherein the hydroxyl groups are primary groups and wherein the hydroxyl groups are located in a position alpha to the conjugated unsaturation in the molecule and compounds which are the polyesters of these compounds with various dibasic acids are highly efiicient gas-producing materials when subjected to heating at decomposition temperatures. These particular types of materials we will refer to hereinafter throughout the specification and the claims as divne-diol compounds and polyesters.

The conjugated diyne-diol compounds when esterified with dibasic acids, such as oxalic, maleic, succinic, adipic, acetylenedicarboxylic or sebacic acid, to form the respective polyesters quite unexpectedly exhibit enhanced gasproducing properties to the extent that the gas-producing propensities of the polyesters are clearly the result of a synergistic action between the dibasic acid and diyne-diol compound.

The diyne-diol compounds of this invention which are useful for preparing the aforementioned polyesters are 3 made 'by an oxidative coupling reaction. For example, propargyl alcohol (2-propyn-l-ol) is subjected to an oxidative coupling reaction to yield 2,4-hexadiyne-l,6-diol according to the following reaction scheme:

Similarly, pent-2-en-4-yn-1-ol is coupled to produce 2,8-

"dec adiene-4,6-diyne-1,10-diol.

, The oxidative coupling reaction used for preparing the diyne-diols of this invention is essentially as described by as a catalyst. Oxygen at atmospheric pressure was added from a measuring burette. Termination of gas absorption was used as the indicator for reaction completion.

These diyne-diol compounds and the related polyesters when subjected to heat decompose vigorously with the evolutionof heat. and gases.

The diyne-diols and the related polyesters were subjected to thermal decomposition tests (IOU-300 C.) in which a mercury filled gas burette was used to determine the volume of gas evolved. The volumes, after correction to standard conditions of temperature and pressure, of typical tests follow.

The first named compound (2,4-hexadiyne-l,6-diol) will evolve on thermal decomposition about 150 milliliters of 'gas, measured at standard temperature and pressure, per gram of material. The second named compound (2,8- :decadiene-4,6-diyne-1,10-diol) will evolve about 200 milliliters of gas, measured under standard temperature and pressure, per gram of material. The same diyne-diol compounds-converted to polyesters via esterification reactions with maleic anhydride, for example, will evolve 350 milliliters of gas, measured under standard temperature and pressure,.per gram of polyester material. The above recited volumes of gas when compared indicate the remarka'ble increase in gas-producing properties that attend the transformation of the diyne-diol compounds to polyesters. In addition, the esterification reactions render the diynediols water insoluble. In contrast, a natural product, isano oil, used in the formulation of conventional intumescent paints, evolves only about 18 milliliters of gas, measured at standard temperature and pressure, per gram of material.

We have discovered that the most effective gas-producing compounds for our purpose are the diyne-diols where in the OH groupings are alpha to the unsaturation. A diyne-diol wherein the OH groups are beta to the unsaturation, 3,5-octadiyne-l,8-diol for example, is no better as a gas producer upon thermal decomposition than is isano oil;

We have discovered additionally that it is important for the hydroxyl groups of the diyne-diol compounds to be primary hydroxyl groups. A disecondary diyne-diol compound, 3,5-octadiyne-2,7-diol, was prepared according to the oxidative coup-ling procedure but gas evolution from this compound upon thermal decomposition was very poor indeed, amounting to only about 33 milliliters of gas, measured under standard conditions of temperature and pressure, per gram of material. Similarly Additionally, we have discovered that combining the aforementioned synthetic zeolites which have been saturatedwith water in the undercoat paint formulations described later herein is a particularly effective means of ter molecule is around 3 Angstrom units, the synthetic zeolites used successfully in this invention have pore size diameters ranging from about 4 to about 13 Angstrom units, permitting water absorption in even the smallest void spaces of any of these materials. These unique properties of the water-saturated synthetic zeolites (known also as molecular sieves) allow their blending into undercoat formulations as gas-producing agents, which formulations possess stability to Water, sunlight, extremes of temperature, and weathering so that they are well-suited for applications in multiple-formulation, exterior paint systems.

Thus, the diyne-diol and butynediol polyesters and the water-saturated, synthetic zeolites of this invention were incorporated into the drying oil alkyds described later in this invention to produce gas-forming undercoats which when covered by a resistant topcoat gives multiple-formulation paint systems which achieve maximum benefits with respect to fire retardance. Superior fire-retardant performance is realized by multiple-formulation paint systems, in which the undercoat or undercoats contain the gas-producing entity and the topcoat is formulated to ob tain some degree of thermal plasticity with respect to the dried film. This retains the gas evolved by the undercoat. Obviously, if the gas evolved as the result of exposure to heat is not retained by the dried protective coating film, the critical protective mat with its inherent insulating effect will not be achieved and the fire re tardance of the coating film will as a consequence be poor. Since the diyne-diol polyesters are highly efficient gas producers we prefer to employ them in the multipleformulation paint systems in which the undercoat is made from specially modified alkyds, such as tung oil-linseed fatty acids trimethylolethane phthalic acid epoxidized soybean oil alkyd, or other modified alkyds as described later herein, and containing from A; to 6% by weight of one of the gas-producing polyester components, and a topcoat which is made from a tung oil-linseed fatty acidstrimethylolethane chlorendic acid diisocyanate alkyd. Since the thermal decomposition of the polyesters results in a rapid evolution of gases and the different polyesters produce different volumes of gases, we prefer to use in this invention from /8 to 2% of the polyesters prepared from 2,4 hexadiyne 1,6 diol or 2,8 decadiene 4,6- diyne 1,10 diol with oxalic acid or maleic acid, from A. to 4% of the polyesters prepared from 2.4 hex diyfie 1,6 diol or 2,8 decadiene 4,6 diyne 1,10 diol with succinic acid or adipic acid, from /2 to 6% of the polyesters prepared from 2,4 hexadiyne 1,6 di-ol or 2,8- decadiene 4,6 diyne 1,10 diol with sebacic acid or acetylenedicarboxylic acid, and from A3 to 6% of the polyesters prepared from butyne 1,4 diol with oxalic acid or maleic acid, to prevent the evolution of too much gases which would rupture the paint film.

On the other hand, the concentration of the watersaturated, synthetic zeolites in the gas-producing undercoat paint formulations is not as critical since high temperatures cause the water-saturated synthetic zeolites to gradually evolve water-vapor gas. We have preferred to use in this invention from A2 to 5% of the gas-producing synthetic zeolite components in combination with the undercoat paint formulations illustrated. These gas-producing undercoat paint formulations are covered with a gasand weather-resistant topcoat as illustrated.

Also, we have found that similarly prepared paint formulations which comprised from /2% to 3% of certain other gas-producing materials, such as cupric carbonate, ferrous oxalate or manganous oxalate, are like wise effective means of producing gas-forming undercoat paint formulations which are operable within the scope of the multiple-formulation paint systems described herein.

Painted test panels prepared in this manner when exposed on a 45-south weathering rack for about fourteen months did not lose any of their initial intumescing fireretardant qualities.

EXAMPLE 1 Preparation of 2,4-hexadiyne-L6-diol The oxidative coupling reaction of 2,4 hexadiyne 1,6- diol was carried out in an aqueous reaction mixture consisting of 56 grams (1 mole) of 2-propyn-1-ol (propargyl alcohol), 230 grams (4.3 moles) of NI-I Cl, 148.5 grams (1.5 moles) of CuCl and 600 milliliters of water. The aqueous solution was adjusted to pH 6.5. The reaction mixture was kept thoroughly agitated at room temperature and oxygen was added under slight pressure to the reaction mixture from a gas burette. The reaction was considered complete when the mixture ceased to absorb oxygen. The entire reaction mixture was extracted with 1800 milliliters of ether, the extract stripped under vacuum to remove the ether and unreacted propargyl alcohol and the extracted reaction mixture finally crystallized from benzene. The yield was 51 grams (about 93 The diyne diol, 2,8 decadiene 4,6 diyne 1,10- diol, was prepared in the same manner using pent-2-en-4- yn-l-ol as the starting material.

EXAMPLE 2 Preparation of the polyesters 12.1 grams (0.11 mole) of 2,4 hexadiyne 1,6 diol, 0.1 mole of dibasic acid, 2-5% of p-toluenesulfonic acid (weight percent based on total solids) and sufficient benzene to produce a 20% solution were added to a 500- milliliter flask equipped with a stirrer, reflux condenser and a moisture trap. The reaction mixture was heated at reflux until the theoretical amount of water was collected in the moisture trap. The polyesters were insoluble in benzene solvent, thus the benzene was mechanically" separated from the reaction mixture and the remaining traces of benzene were removed under vacuum. The above described procedure was carried out using oxalic acid, succinic acid, adipic acid, sebacic acid, maleic acid, acetylene dicarboxylic acid, and o-phthalic acid. Each of the dibasic acids except phthalic acid when incorporated with the diyne-diol compounds to produce a EXAMPLE 3 Preparation of tung oil alkyds The procedure employed to prepare the various types of tung oil alkyds is essentially as described by Leo A. Goldblatt, Lucien L. Hopper, Jr. (Fellow of the Pan American Tung Research and Development League), and Eric T. Rayner, US. Patents #2,999,104 and 3,008,910.

(1) The tung oil, tung oil-cottonseed oil, or tung oildehydrated castor oil and 50% of the trimethylolethane were alcoholized and gasproofed in the presence of 0.03%

of the mixture was reduced to 280 C., then the linseed fatty acids, the other 50% of the trimethylolethane, and

2% triphenyl phosphite were added. This mixture was 'esterifiedat about 250 C. until -90% of the theoretical amount of water of esterification was evolved. (3) Depending upon the dibasic acid used, the procedure was varied as follows: (a) When isophthalic acid was used, the temperature of the mixture was reduced to 180 C.; then the isophthalic acid was added. The mixture was esterified at about 230 C. until practically all the water of esterification was removed (acid value of about 9). (b) When phthalic anhydride was used, the temperature of the mixture was reduced to 180 C., then the anhydride and a few milliliters of benzene were added, the latter to remove the water of esterification azeotropically and to prevent the phthalic anhydride from subliming. This mixture was esterified between 200 and 250 C. until most of the water of esterification was removed azeotropically (acid value of about 20). (c) When chlorendic (1,4,5 ,6,7,7-hexachlorobicyclo-(2.2.1)-5 hep- Ftene-2,3-dicarboxylic) acid was used, the temperature of *the mixing was reduced to 150 C.; then the chlorendic v acid and several milliliters of benzene were added. The mixture was esterified at about 180 C. under reflux until practically all of the water of esterification was removed azeotropioally (acid value of about 6). (d) When dimerized linoleic acid was used, the temperature of the mixture was reduced to 160 C.; then the dimerized linoleic acid and several milliliters of benzene was added. The mixture was esterified at about 220 C. under reflux until practically all of the water of esterification was removed azeotropically (acid value of about 8). (4) 'When ep-oxidized soybean oil was used, the temperature of the mixture in (3b) was reduced to 120 C. after the acid value of the mixture was reduced to about 20; then the epoxidized soybean oil was added and the temperature was kept at about 120 C. until the acid value was reduced to about 10 (usually took about 4 hours at 120 C.). (5) \Vhen either tolylene diisocyanate or trichlorophenyl diisocyanate was used, the temperature was reduced to about C.; then the alkyd was diluted to about 70% solids with mineral spirits. The respective diisocyanate and 0.01% diethylethanolamine catalyst were added and the mixture was heated between and C. for 2 hours. Several milliliters of absolute ethanol was added after standing overnight to prevent excessive crosslinking upon aging.

Several dozen alkyds were prepared by the procedures described above, and evaluated with gas-producing components. The formulations are long, long oil alkyds which are thought to be-particularly essential to impart plasticity and softness, and to minimize brittleness so that the gases evolved from the gas-producing components in the intumescing paint film will be confined and retained by the vehicle, the whole mass becoming the protective insulating barrier. Of these, the drying oil modified alkyds which can be employed most advantageously to prepare gas-producing undercoats with the gas-producing mate- .rials of this invention are shown below:

Tung oil 100 Linseed oil fatty acids 100 Trimethylolethane 35 Phthalic anhydride 33 Epoxidized soybean oil (90%) 25 Tung oil 100 Linseed oil fatty acids 100 Trimethylolethane 35 'Isophthalic acid 19 Tolylene diisocyanate 19 These'alkyds, the gas-producing components, pigments, and other paint ingredients can be formulated into gasproducing paint formulations as illustrated below.

If desired, these formulations can be prepared without incorporation of the pigments listed to produce non-pigmented, gas-producing paint vehicles.

Mineral spirits was added to these gas-producing .paint vehicles or formulations as needed to adjust their final viscosity within a range of about 80 to 100 Krebs units, but We prefer to employ them for this invention at about 90 Krebs units viscosity.

As will be recognized by those skilled in the art, coating thickness and ease of spreading (brushability) are the use 40 factors related to viscosity and for the purposes of the instant invention final viscosities of about 90 Krebs units are best.

FORMULATION A Percent Percent Pigment and Other Solid Components Pigment Total f" Paint Titanium Dioxide..- 11.87 1 7. 48 Zinc Borate 35.00 22. 06 Magnesium Silicate (Mistron 1. 75 1. 10 Lead'Sulfate 19.95 12. 57 Lead Carbonate. 19.95 12. 57 Zinc Oxide 11.26 7. 09 Polyester of 2,4-hexadiyne-l,6-d1ol and maleic acid 0.21 0.13

Total Pigment and Other Solids 100.00 63.00

' Percent Percent Non-volatile Vehicle Components Vehicle of Total Paint Alkyd a 35. 14 13.00 Refined Linseed Oil 35.14 13. 00 Chlorinated Parafl'in 70%- 15. 48 5. 73 Polyarm'de Resin (V ersamid 12.98 4. 80 Cobalt Naphthenate Solution (6% Metal). 0. 13 0.05 Lead N aphthenate Solution (24% Lead as Metal 0. 59 0. 22 Anti-Skinning Agent (National ASA) 0.27 0.10 Ultra Violet Screening Agent (Uvinul #490). 0.27 0.10

Total Non-volatile Vehicle 100.00 37.00

Total Paint Non-volatiles 100.00

Mineral spirits was added to adjust final paint viscosity to about 90 Krebs units.

FORMULATION 13 Percent Percent Pigment and Other Solid Components Pigment of Total Paint Titanium Dioxide 11.86 7. 47 Zinc Borate 34.95 22.02 1. 73 1. 09 19. 92 12. 55 19. 92 12. 55 11.22 7.07 Polyester of 2,4-hexadiyne-L6-diol and Maleic Acid 0.40 0.25

Total Pigment and Other Solids 100.00 63.00

Percent Percent Non-volatile V ehiele Components Vehicle of Total Paint Alkyd a 35. 14 13. 00 Refined Linseed Oil 35.14 13. 00 Chlorinated Paraflin 70%. 15. 48 5. 78 Polyamide Resin (Versamid 93 12. 98 4.80 Cobalt Napththeuate Solution (6% Cobalt as Metal) 0. 13 0.05 Lead Naphthenate Solution (24% Lead as Metal) 0. 59 0. 22 Anti-Skinning Agent (National ASA) 0.27 0.10 Ultra Violet Screening Agent (Uvinul #490)- 0.27 0. 10

Total Non-volatile Vehicle 100.00 37.00

Total Paint Non-volatiles 100.00

Mineral spirits was added to adjust final paint viscosity to about 90 Krebs units.

b Alkyd was added as a mineral spirits solution of 5080% solids content c Sixty-four grams General Mills Versarnid #930 was dissolved in 41 grams n-butanol by heating, then 75 grams of mineral spirits was added.

FORMULATION C Percent Percent Pigment and Other Solid Components Pigment of Total Paint Titanium Dioxide 11. 70 6.55 Zine Borate 34. 47 19.30 Magnesium Silicate (Mistron #5). 1. 71 0.96 Lead Sul 19. 64 11.00 Lead Carbonate. 19.64 11.00 Zinc Oxide 11.05 6.19 Synthetic Zeolite (Union Carbides MS-5A saturated with water) 1. 79 1.00

Total Pigment and Other Solids 100.00 56.00

Percent Percent Non-volatile Vehicle Components Vehicle of Total Paint Alkyd a b 37. 50 Refined Linseed on 31.50 Chlorinated Paraffin 70% 12. 73 5. Polyamide Resin (Versamid #930) 9. 76 4. 29 Cobalt Naphthenate Solution (6% Cobalt as Metal 0.36 0.16 Lead N aphthenate Solution (24% Lead as Metal) T 1. 47 0. Anti-Sk nning Agent (National ASA) 0.34 0. 15 Ultra Violet Screening Agent (Uvinul #490) 0. 34 0.15

Total Non-volatile Vehicle 100. 00 44.00

Total Paint Non-volatiles 100.00

a Mineral spirits was added to adjust final paint viscosity to about 90 Krebs umts. te gilkyd was added as a mineral spirits solution of 50-80% solids con- Sixty-four grams General Mills Versamid #930 was dissolved in 41 grams n-butanol by heating, then grains of mineral spirits was added FORMULATION D FORMULATION F Percent Percent Pigment and Other Solid Components Pigment of Total Percent Percent Paint Pigment and Other Solid Components Pigment of Total Paint 5 Titanium Dioxide 11. 90 7. 50 Zinc Borate 35.08 22.10 ltfl m lo ide 1 6 72 Magnesium Silicate (Mistron #5) l. 75 1. 10 Zinc Borate 34. 38 16.84 L 1 Sulfate 20.00 12. 60 Magnesium Silicate 1. 71 0. 84 L Carbonate 20, 12. 60 Lead Sulfate. 19. 59 9. 60 Zinc O id 11.27 7- 10 Lead Carbonate. 19. 59 9. 60 21110 0x1 de 11. 02 40 Total Pigment and Other Solids 100. 00 63. 00 Synthetic Zeolite saturated 2. 04 1.00

Total Pigment and Other Solids 100. 00 49.00 Percent Percent Non-volatile Vehicle Components Vehicle oglottal am Percent Percent Non-volatile Vehicle Components Vehicle of Total Palm Raw Isano 011 35.14 13. 00 Refined Linseed Oil 35.14 13.00 Chlorinated Paraifin 70% 15. 48 5. 73 Alkyd a b 39- -00 Polyarnide Resin (Versamid #930) 12. 98 Refi e s d O 1 3912 20-00 Cobalt Naphthenate Solution (6% Cobalt as Chlorinated Paraffin 70%. 9. 84 5.02 M tal) 0.13 0.05 Polyamide Resin (V ersamid #930) 9. 02 60 00 Lead Naphthenate Solution (24% Lead as Cobalt Naphthenate Solnt1on (6% Cobalt as M tal 0.59 0.22 Metal) 39 20 Anti-Skinning Agent (National ASA) 0.27 a r llqaphthenatc Solution a as 1 53 0 78 UltraViolet Screening Agent (Uvinul #490--- 0. 27 0.10

l e a Anti-Skinning Agent (National ASA) O. 39 0- 20 Total Non-volatile Vehicle 100. 00 37. 00 Ultra Violet Screening Agent (Uvinul #490)-.- 0.39 0.20 Total Paint Non-volatiles 100.00 Total Non-volatile Vehicle 100. 00 51.00 20 Total Paint Nonwolatiles 100 00 Kselglinlelriazls spirits was added to adjust final paint viscosity o about 90 b Sixty-font grams General Mills Versamid #930 was dissolved in 41 M dd d d 1 t b t 0 grams n-butanol by heating, then 75 grams of mineral spirits was added lneral i 't as to a u t fi ant 0s to a on 9 Krebs n S a e 1 S p 1 1 y Typical drying 011 modified alkyds which can be emb lliydf was added 1 amirieiga llslpirgs solutig )80%ds0li(}s cgnitenlil. 30 ployed advantageously to prepare resistant topcoats for v ix your grams enera ii 5 ersami was isso ve n grams n-bntanol by heating, then 75 grams of mineral spirits was added these gas'producmg undercoats a Shown below Tung oil 100 Linseed oil fatty acids 1 00 Trirnethylolethane 35 Chlorendic acid 43 Tolylene diisocyanate 19 40 Tung 011 100 Linseed oil fatty acids 100 Trimethylolethane 35 Chlorendic acid 43 Trichlorophenyl diisocyanate 29 45 These alkycls, pigments, and other paint ingredients can be formulated into weatherand gas-resistant, topcoat FORMULATION E paint formulations as illustrated below:

FORMULATION G Percent Percent Pigment and Other Solid Components Pigment of Total r Percent Percent Palm; Pigment and Other Solid Components Pigment of Total Paint itanliaum Dioxide 2;. inc crate 1 Magnesium Silicate (Mistron 1. 75 1.10 fi Lead Sulfate 20-00 6 Magnesium Silicate (Mistron #5) l. 75 1.10 e Carbonate" 20-00 Lead Sulfate 20.00 12.60 Z1110 Oxide 27 Lead garibonate" 20.00 12. Total Pigment and Other Solids 100.00' 63.00 Zinc e 10 Total Pigment and Other Solids 100.00 63.00

Percent Percent Non-volatile Vehicle Components Vehicle of Total 60 Percent Percent Palm Non-volatile Vehicle Components Vehicle of Total Paint Refined {ai lsleed (3 11 7.? 2'; 2g 3g Chlorina e are n 0 A11; d i b 27 2 00 Poly mi e Resin (V ld 98 chigmmted Paraflin 70% 15, 49 5. 73 Cobalt Naphthenate Solutwn Cobalt as Polyamide Resin (Versamid #930 13.46 4.98

013 M5 60 Cobalt Naphthenate Solution (6% Cobalt as Lead Na Solution (24% Lead as m 0 05 [102 Metal). 59 22 Lead Na Anti-Skin g Agent (National ASA) 27 10 M t- 1) 119 0 07 Ultra Violet Screening Agent (Uvinul #490)". 0. 27 O. 10 Anti skinning Agent (National 0 7 0. 10 Ultra Violet Screening A ent U inul #4 0.27 0. 10 Total No -vo atile Vehicle 00 00 Total Non-volatilg Vel iic1 e 100.00 37. 00 Total Paint No o 00 70 Total Paint Non-volatiles. 100. 00

lgineral spirits was added to adjust final paint viscosity to about z g g g was added to adjust final Paint Viscosity to about 90 Kre sunits. bAk

- Y yd was added as a mineral spirits solution of 50-807 solids content. g g gg gi b gfig g 3 9 53 3? 5 335 g'z g ggggg g c Sixty-four grams General Mills Versamid #930 was dissolved in 41 g y 75 grams n-butanol by heating, then 75 grams 01' mineral spirits was added Preparation 0 fire-retardant paint films One or two coats (about 3 to 4 mils per coat) of the gas-producing undercoat paint formulations were spread with a brush on poplar heartwood panels ('6 x 12 x inches). Then a coat of the Weatherand gas-resistant topcoat paint formulation was applied. The different coats were applied about 24 hours apart. The procedure listed in Federal Specification TTP34a was followed as closely as possible. The total weight of paint on each panel was computed after the paint films had been cured for about 2 weeks, but the weight of the undercoat or undercoats was determined as soon as they were tack-free.

Evaluation of fire-retardant paint films The cured paint films were evaluated according to Federal Specification TT-P-34a with a standard fire test cabinet (New York Paint and Varnish Production Club Test Cabinet). Some of the paint films were evaluated for their fire retardancy before leaching, some after leaching, and other after weathering for about 14 months. Numerous diiferent types of intumescing fire-retardant paint formulations were developed and evaluated. The data obtained from representative examples is illustrated in Table I.

We claim:

1. A flammable base having thereon a fire-retardant undercoat comprising an oil modified alkyd resin vehicle having incorporated therein a gas-producing component consisting of a polyester of a conjugated diyne-diol in which the hydroxyl groups are primary and a dibasic acid of the group consisting of oxalic, maleic, succinic, adipic, sebacic, and butynedioic acids and a top coat comprising about 26 weight percent of an alkyd made from 100 parts tung oil, 100 parts linseed oil fatty acids, 35 parts trimethylolethane, 43 parts chlorendic acid, and from 19 to 29 parts of a diisocyanate from the group consisting of toluene diisocyanate and trichlorophenyl diisocyanate, about 6 weight percent of 70% chlorinated paraffin, about 5 weight percent of the polyamide of dimerized linoleic acid and ethylenediamine and about 63 weight percent of a pigment component made from 12 parts titanium dioxide, 35 parts zinc borate, 2 parts magnesium silicate, 20 parts lead sulfate, 20 parts lead carbonate, and 12 parts zinc oxide.

2. A flammable base having thereon a fire-retardant undercoat comprising an oil modified alkyd resin vehicle having incorporated therein a gas-producing component consisting of a polyester of 2-butyne-1,4-diol and a dibasic TABLE I.--EVALUATION OF TWO- AND THREE-COAT PAINT FILMS, PREPARED FROM SINGLE AND MULTIPLE FORMULATIONS FOR THEIR FIRE RETARDANOY BEFORE LEACHING, AFTER LEAOHING,AND AFTER WEATHERING, ACCORDING TO FED- ERAL SPECIFICATION TT-P-34a a Paint Formulations Paint on panel (gms) Panel weight loss after fire retardancy evaluation (gins) Undereoats Under Topcoat Topeoat Total Nonleached Leached Weathered b coat 1st 2nd 15.2 14.6 15. 7 15. 6 l5. 4 15.2 15.5 15. 2 15.4 15.5 15. 7 l5. 9 B G 10.6 15.5 15. 4 15.8 .1 l5. 1 15.9 16.0 15.0 15.7 15.5 15.9 15.1 15.4 15. 4 15. 1 16. 3 C G 14. 9 13. 9

15. 2 14. 4 15.5 15. 5 15.5 14. 6 15.3 14. 8 15. 5 15. l 15. 9 14. 9 D G 15.0 15.2 14. 0 15.4 15. 9 14. 6 E None 13. 8

F 12. 6 12. 4 H-l c None 13. 6 14.6 14.6 13. H-Z 11-3 11.5 12.5

12.8 12.8 11-2 z G 12.1 12.4 12. 4 12.7 12.5 12. 5 H-2 6 16. 3 13.0 16. 7 13.3 11-4 h 12. 2 12. 4

H Details of experimental procedure are given in Federal Specification TT-P-34a. These are average results obtained fiOIIl duplicates or triplicates.

b These test specimens were exposed to natural weathering, facing South under 45, for about 14 months in New Orleans.

0 A commercial, exterior, intumescing fire-retardant paint formulation. The test specimen began to crack after several months exposure, followed by extensive cracking after 14 months.

= A commercial intumescing fire-retardant paint formulation.

i A commercial, exterior paint formulation employed as a resistant topcoat for paint formulation H-2. 2 The test specimens were evaluated for their fire retardancy after only two months exposure because of extensive peeling and cracking.

A commercial, interior, intumescing fire-retardant paint formulation.

acid of the group consisting of oxalic and maleic acids and a top coat comprising about 26 Weight percent of an alkyd made from 100 parts tung oil, 100 parts linseed oil fatty acids, 35 parts trimethylolethane, 43 parts chlorendic acid, and from 19 to 29 parts of a diisocyanate from the group consisting of toluene diisocyanate and trichlorophenyl diisocyanate, about 6 weight percent of 70% chlorinated parafiin, 5 weight percent of the polyamide of dimerized linoleic acid and ethylenediamine and about 63 weight percent 01 a pigment component made from 12 parts titanium dioxide, 35 parts zinc borate, 2 parts magnesium silicate, 20 parts lead sulfate, 20 parts lead carbonate, and 12 parts zinc oxide.

3. A flammable base having thereon a fire-retardant undercoat comprising an oil modified alkyd resin vehicle having incorporated therein a gas-producing component consisting of an alkali metal aluminosilicate saturated with water and a top coat comprising about 26 weight percent of an alkyd made from 100 parts tung oil, 100 parts linseed oil fatty acids, 35 parts trimethylolethane, 43 parts 20 chlorendic acid, and from 19 to 29 parts of a diisocyanate from the group consisting of toluene diisocyanate and trichlorophenyl diisocyanate, about 6 weight percent of 70% chlorinated paraflin, about 5 Weight percent of the polyamide of dimerized linoleic acid and ethylenediamine and about 63 weight percent of a pigment component made from 12 parts titanium dioxide, 35 parts zinc borate, 2 parts magnesium silicate, 20 parts lead sulfate, 20 parts lead carbonate, and 12 parts zinc oxide.

References Cited by the Examiner UNITED STATES PATENTS 1,784,135 12/1930 Ellis 11790 X 1,867,658 7/1932 Dreyfus 117-137 X 1,885,870 11/1932 Snyder 1l7-137 2,804,398 8/1957 Hooks 117-136 X 2,813,046 11/1957 Lauring 117-72 2,821,514 1/1958 Sarbach et al 117137 WILLIAM D. MARTIN, Primary Examiner.

R. HUSACK, Assistant Examiner. 

1. A FLAMMABLE BASE HAVING THEREON A FIRE-RETARDANT UNDERCOAT COMPRISING AN OIL MODIFIED ALKYD RESIN VEHICLE HAVING INCORPORATED THEREIN A GAS-PRODUCING COMPONENT CONSISTING OF A POLYESTER OF A CONJUGATED DIYNE-DIOL IN WHICH THE HYDROXYL GROUPS ARE PRIMARY AND A DIBASIC ACID OF THE GROUP CONSISTING OF OXALIC, MALEIC, SUCCINIC, ADIPIC, SEBACIC, AND BUTYNEDIOIC ACIDS AND A TOP COAT COMPRISING ABOUT 26 WEIGHT PERCNET OF AN ALKYD MADE FROM 100 PARTS TUNG OIL, 100 PARTS LINSEED OIL FATTY ACIDS, 35 PARTS TRIMETHLOLETHANE, 43 PARTS CHLORENDIC ACID, AND FROM 19 TO 29 PARTS OF A DISOCYANATE FROM THE GROUP CONSISTING OF TOLUENE DIISOCYANATE AND TRICHLOROPHENYL DIISOCYANATE, ABOUT 6 WEIGHT PERCENT OF 70% CHLORINATED PARAFFIN, ABOUT 5 WEIGHT PERCENT OF THE POLYAMIDE OF DIMERIZED LINOLEIC ACID AND ETHYLENEDIAMINE AND ABOUT 63 WEIGHT PERCENT OF A PIGMENT COMPONENT MADE FROM 12 PARTS TITANIUM DIOXIDE, 35 PARTS ZINCH BORATE, 2 PARTS MAGNESIUM SILICATE, 20 PARTS LEAD SULFATE, 20 PARTS LEAD CARBONATE, AND 12 PARTS ZINC OXIDE. 